Mass-productive free-standing ZnO nanotripods were obtained by thermal chemical vapor deposition without introduction of catalysts and substrates. Three arms of ZnO nanotripods had lengths ranging from 300 nm to 1.0 mu m and a single-crystal line hexagonal structure. It was found that an inverted triangle-shaped zinc blende ZnO core is located at the center of the grown ZnO nanotripod and a twin structure exists at the interface between each arm. The three arms with extremely narrow diameters below 20 nm were grown along to the [0 0 0 1] c-axis and the twin boundary was identified as (0 1 (1) over bar 3). ZnO nanotripods exhibited a relatively weak deep-level emission band as well as strong near band-edge emission in the room-temperature photoluminescence measurement, indicating the high optical quality and low defect density of the ZnO nanotripods. (C) 2008 Elsevier B.V. All rights reserved.